Health care workers have a continued risk of exposure to infectious agents because of needle stick injuries. Injury can occur during recapping of the needle or from uncapped or improperly stored needles. Health departments are recommending that needles should not be recapped, purposely bent, broken, removed from the disposable syringes or otherwise manipulated by hand in order to avoid accidental puncture injury. It has been further recommended that all needles should be regarded as potentially infective and handled with extraordinary care to prevent accidental injuries. To mitigate the risk of inadvertent puncture, it is recommended that disposable needles should be placed in puncture resistant containers which should be as close as practical to the area in which the needles will be used. However, it is practically impossible to put puncture resistant containers in every patient's room and in every office of a medical facility. Therefore, the needles that have been used must be transported to a puncture resistant container.
The U.S. Pat. Nos. 3,134,380 to Armao, issued May 26, 1964; 3,658,061 to Hall, issued Apr. 25, 1972; and 4,139,009 to Alvarez, issued Feb. 13, 1979, all relate to hypodermic needle assemblies with covers or guards which attempt to shield a used hypodermic needle after use. The Hall patent discloses a catheter needle guard unit including a hub with a cannula needle affixed thereto and a needle guard including a sleeve member with a longitudinal slot adapted to snap over the entire length of the needle. In operation, the needle guard is in the open position when the needle is used to make a venipuncture in a patient and snapped into the closed position manually by a finger of the operator after withdrawal of the needle. The assembly does not totally enclose the needle shaft or the needle tip. The assembly further requires the technician to force the needle guard towards the needle tip allowing for the possibility of either the guard slipping from the technician's grip or the technician missing the needle guard, resulting in accidental puncture. Also, if the needle is bent during use, the sleeve is either prevented from covering the needle or will not contain the entire needle.
The Armao and Alvarez patents both disclose retractable needle guards which extend over the length of the needle assembly prior to use and are retracted as the needle is inserted into the patient. These assemblies require the technician to force the guard to retract as the needle is being inserted. Both guards also do not completely cover the needle tip and can be readily retracted by pressure to the end of the needle guard. Accordingly, accidental puncture can occur merely by the technician accidently depressing the needle guard.
ICU Medical Inc., Huntington Beach, Calif. manufactures a needle marked as "ICU HIGH RISK.TM.". The assembly includes locking members mounted on the needle shaft and a shield which has a neutral position against the hub and an extended position over the needle tip. The shield is moved from the hub, over the locking member, and locked with the locking member as the shield is moved to the extended position.
The Armao, Alvarez, and ICU Medical, Inc. assemblies all include a shield which cover a significant portion of the needle shaft during use of the needle for an injection. Hence, the assemblies either have less usable needle length if a conventional needle is adapted to the assembly, or the assemblies require a significantly longer needle shaft. Additionally, all these assemblies leave the tip of the needle exposed or capable of being exposed. The tip of the needle is not locked in a completely enclosed guard.
The present invention solves the aforementioned problems by providing a needle guard which does not require a technician to force the needle guard to a retracted position during insertion of the needle, and further essentially irreversibly covers the needle tip. The invention further provides more usable needle length making it adaptable to presently manufactured needle assemblies.